... quality PCB with compititive price certified PCB Blue solder mask ROHS BLUE SOLDER MASK PCB Item Manufacture Capability Layers 1-20 Layers ... .125mm, Punching:+/-0.15mm Warp &Twist 0.70% Min. Solder Mask Bridge 0.0635mm Distance Between Line to Board Edge Outline ... .40mm Impedance Control Tolerance +/-10% Test Voltage 10-300V Solder Mask Types White, Blue, Matt Green, Matt Black etc. Surface Finishing ...